Observing and monitoring microscopic objects in a suspension, such as cells in a bio-reactor, is a necessity in many present-day applications related to biology, chemistry, physics, environmental science, etc. A multitude of systems is known which allow such monitoring for specific applications.
Microscopic objects present in suspension in a vessel could be difficult to monitor by microscopy for a number of reasons, such as the continuous movement of the objects due to e.g. small currents in the suspension liquid, the opacity of the liquid or the size of the vessel. Usually, microscopy is performed on small samples. One possible way of monitoring objects in suspension in a storage vessel by microscopy is to manually take small samples from the suspension on a regular basis for viewing under a microscope. It is clear that such a manual procedure is not suitable for monitoring of a large number of suspensions located in a multitude of vessels.
One solution is to provide a transport system, which is capable of guiding the suspension towards a microscope. Such a transport system may take the form of a fluidics system, wherein typically a pumping mechanism transports the suspension from and, if desired, to the storage vessel. For instance, patent application US 2010/0315501 A1 discloses an electronic imaging flow-microscope for remote environmental sensing, bioreactor process monitoring, and optical microscopic tomography applications. Hereby, a fluid conduit has a port on each end of a thin flat transparent fluid transport region. A planar illumination surface contacts one flat side of the transparent fluid transport region and a planar image sensing surface contacts the other flat side. Light from the illumination surface travels through the transparent fluid transport region to the planar image sensing surface, producing a light field affected by the fluid and objects present. The planar image sensing surface creates electrical image signals responsive to the light field. The planar illumination surface can be light emitting elements such as LEDs, OLEDs, or OLET, whose illumination can be sequenced in an image formation process. The flow microscope can further comprise flow-restricting valves, pumps, energy harvesting arrangements, and power management. Although the use of such a fluidics system constitutes an improvement over manually taking samples in a large-scale monitoring set-up, there remains a problem of ensuring a connection of the fluidics system with the suspensions in the storage vessels. In fact, the fluidics system of US 2010/0315501 is suitable for long-time monitoring of the suspension in one specific vessel, but may be difficult to use in practice for monitoring or observing suspensions in a multitude of vessels using only one microscopic system. Furthermore, connecting such fluidics system to a vessel is a time-consuming manual process, which does not lend itself to be automated.
There remains a need in the art for an improved system and method for the observation or monitoring of objects in suspension in a vessel, which allows an automated observation or monitoring by a microscopic system of the suspensions in a multitude of vessels without a need of reconnecting fluidic tubing or the like. There remains a need in the art for an improved system and method for the observation or monitoring of objects in suspension in a vessel, whereby the vessel is closed off before, during and after the monitoring, thereby remaining sterile. There remains a need in the art for an improved vessel and cap which are cheap and easy to transport and store.
The present invention aims to resolve at least some of the problems mentioned above. The invention thereto aims to provide a cap for a vessel comprising a fluidics system which comprises a measurement region. The present invention also aims to provide a method and system for observing or monitoring a suspension in a vessel, suitable for monitoring suspensions in a multitude of vessels with one microscope.